Fizikalna i antioksidacijska svojstva mješavina prahova kakaa i sladila te pripremljenih napitaka

master's thesis

• Title (english): Physical and antioxidant properties of powdered mixtures and drinks prepared with cocoa and various sweeteners
• Author: Mateja Matijašec
• Mentor: Draženka Komes (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Chemistry and Technology of Carbohydrates and Confectionery Products); Zagreb
• Defense date and country: 2010-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Proteklih godina velika pažnja posvećena je analizi bioaktivnih sastojaka različitih kakaovih proizvoda, no utjecaj dodatka različitih sladila na njihova fizikalna, kemijska i senzorska svojstva te bioaktivni sastav je relativno slabo istražen. U ovom radu određena su fizikalna svojstva mješavina za kakaov napitak te bioaktivni sastojci i senzorska svojstva kakaovog napitka. Određivana je veličina čestica, nasipna gustoća te indeks kohezije šećera i sladila kao i mješavina za kakaove napitke. Udio polifenola određivan je UV/VIS spektrofotometrijskim metodama, a antioksidacijski kapacitet ABTS (2,2'-azinobis-(3-etilbenzotiazolin-6 sulfonska kiselina)) metodom. Mješavine prahova za kakaov napitak pokazale su visoku antioksidacijsku aktivnost i imaju visok udio polifenolnih spojeva. Vrsta sladila nije značajno utjecala na udio polifenola. Mješavine koje su imale dobra senzorska svojstva karakterizirane su lošim fizikalnim karakteristikama. Dobiveni rezultati pokazuju mogućnost primjene alternativnih sladila za pripremu kakaovih napitaka koji će uz dobra fizikalna i senzorska svojstva poboljšati i njihova antioksidacijska svojstva.

Abstract (english)

In recent years great attention has been paid to the analysis of bioactive constituents of various cocoa products, but effect of the addition of sweetener type on physical, sensory and chemical properties and bioactive constituents of the reconstituted drinks has been in some extent disregarded. Particle size, bulk density and cohesion index of the used sugars and sweeteners, as well as the formulated mixtures were determined. In order to compare the content of polyphenols in the formulated cocoa drink mixtures, UV/VIS spectrophotometric methods were applied and antioxidant capacity of cocoa drinks was evaluated by using ABTS assay. Cocoa powder mixtures delivered a beneficial amount of polyphenolic compounds, as well as a high antioxidant efficiency, whereas the type of sweetener did not influence their polyphenolic content. While the sensory preferences increased with the addition of sweeteners, those mixtures resulted with poor physical properties. The displayed results indicate the significant potential of using alternative sweeteners for the preparation of cocoa drink mixtures, which may provide good physical and sensory properties and also enhance the already existing beneficial effects of cocoa.

• Keywords: antioksidansi; fizikalna svojstva; kakao; senzorska analiza; sladila
• Keywords (english): antioxidants; cocoa; physical properties; sensory evaluation; sweeteners
• Language: croatian
• URN:NBN: urn:nbn:hr:159:160085
• Study programme: Title: Food Safety Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane (magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-08-25 12:43:15